The present invention relates to a camera which can adjust the distance between a photographing lens and a film loaded in the camera and an f-number of a diaphragm according to the photographing control condition, and more specifically to a camera in which a simple auto-focusing operation and an auto-exposure operation are accomplished.
Conventionally, a camera includes a shutter mechanism, a diaphragm mechanism and a focusing mechanism etc. that are adjustable. The shutter mechanism, the diaphragm mechanism and the focusing mechanism are adjusted according to a photographing control condition such as object distance, object brightness and film sensitivity. Recently, these mechanism have tended to be automatically adjusted. In order to accomplish the automatic adjustment, the f-number of the diaphragm mechanism is changed by means of an auto-exposure mechanism (i.e., an AE mechanism) according to the object brightness detected by an object brightness measuring sensor, and the distance between the photographing lens and the film is changed by means of an auto-focusing mechanism (i.e., an AF mechanism) according to the object distance detected by an object distance measuring sensor.
However, in the auto-focus mechanism it is necessary to employ a drive mechanism for moving the photographing lens to change the distance between the photographing lens and the film, and in auto-exposure mechanism it is necessary to employ another drive mechanism for changing the size of the diaphragm aperture. These drive mechanisms are relatively expensive to manufacture. Therefore, the cost of the camera tends to increase if both an AE mechanism and an AF mechanism are employed in the camera. Then, it is difficult to make a low-cost camera equipped with both an AE mechanism and an AF mechanism.